Make GraphiQLController an abstract class with two subclasses, one for servlet and one for reactive. Adjust the autoconfiguration accordingly.

Author: Ronny Bräunlich

graphiql-spring-boot-autoconfigure/build.gradle

@@ -23,6 +23,7 @@ dependencies{
     compile "org.apache.commons:commons-text:1.1"
     compileOnly "org.springframework.boot:spring-boot-starter-web:$LIB_SPRING_BOOT_VER"
     compileOnly "org.springframework.boot:spring-boot-starter-security:$LIB_SPRING_BOOT_VER"
+    compileOnly "io.projectreactor:reactor-core:3.3.0.RELEASE"
 
     testCompile "org.springframework.boot:spring-boot-starter-web:$LIB_SPRING_BOOT_VER"
     testCompile "org.springframework.boot:spring-boot-starter-test:$LIB_SPRING_BOOT_VER"

graphiql-spring-boot-autoconfigure/src/main/java/com/oembedler/moon/graphiql/boot/GraphiQLAutoConfiguration.java

@@ -1,26 +1,36 @@
 package com.oembedler.moon.graphiql.boot;
 
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.web.servlet.DispatcherServlet;
 
+import static org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication.Type.SERVLET;
+import static org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication.Type.REACTIVE;
+
 /**
  * @author Andrew Potter
+ * @author Ronny Bräunlich
  */
 @Configuration
-@ConditionalOnWebApplication
-@ConditionalOnClass(DispatcherServlet.class)
+@ConditionalOnProperty(value = "graphiql.enabled", havingValue = "true", matchIfMissing = true)
 @EnableConfigurationProperties(GraphiQLProperties.class)
 public class GraphiQLAutoConfiguration {
 
-    @Bean
-    @ConditionalOnProperty(value = "graphiql.enabled", havingValue = "true", matchIfMissing = true)
-    GraphiQLController graphiQLController() {
-        return new GraphiQLController();
+    @Bean(name = "graphiQLController")
+    @ConditionalOnWebApplication(type=SERVLET)
+    ServletGraphiQLController servletGraphiQLController() {
+        return new ServletGraphiQLController();
     }
 
+    @Bean(name = "graphiQLController")
+    @ConditionalOnMissingBean(ServletGraphiQLController.class)
+    @ConditionalOnWebApplication(type=REACTIVE)
+    ReactiveGraphiQLController reactiveGraphiQLController() {
+        return new ReactiveGraphiQLController();
+    }
 }

graphiql-spring-boot-autoconfigure/src/main/java/com/oembedler/moon/graphiql/boot/GraphiQLController.java

@@ -30,8 +30,7 @@
  * @author Andrew Potter
  */
 @Slf4j
-@Controller
-public class GraphiQLController {
+public abstract class GraphiQLController {
 
     private static final String CDNJS_CLOUDFLARE_COM_AJAX_LIBS = "//cdnjs.cloudflare.com/ajax/libs/";
     private static final String CDN_JSDELIVR_NET_NPM = "//cdn.jsdelivr.net/npm/";
@@ -48,7 +47,6 @@ public class GraphiQLController {
     private String props;
     private Properties headerProperties;
 
-    @PostConstruct
     public void onceConstructed() throws IOException {
         loadTemplate();
         loadProps();
@@ -78,23 +76,20 @@ private void addIfAbsent(Properties headerProperties, String header) {
         }
     }
 
-    @GetMapping(value = "${graphiql.mapping:/graphiql}")
-    public void graphiql(HttpServletRequest request, HttpServletResponse response, @PathVariable Map<String, String> params) throws IOException {
-        response.setContentType("text/html; charset=UTF-8");
-        Object csrf = request.getAttribute("_csrf");
+    public byte[] graphiql(String contextPath, @PathVariable Map<String, String> params, Object csrf) {
         if (csrf != null) {
             CsrfToken csrfToken = (CsrfToken) csrf;
             headerProperties.setProperty(csrfToken.getHeaderName(), csrfToken.getToken());
         }
 
         Map<String, String> replacements = getReplacements(
-                constructGraphQlEndpoint(request, params),
-                request.getContextPath() + graphiQLProperties.getEndpoint().getSubscriptions(),
-                request.getContextPath() + graphiQLProperties.getSTATIC().getBasePath()
+                constructGraphQlEndpoint(contextPath, params),
+                contextPath + graphiQLProperties.getEndpoint().getSubscriptions(),
+                contextPath + graphiQLProperties.getSTATIC().getBasePath()
         );
 
         String populatedTemplate = StrSubstitutor.replace(template, replacements);
-        response.getOutputStream().write(populatedTemplate.getBytes(Charset.defaultCharset()));
+        return populatedTemplate.getBytes(Charset.defaultCharset());
     }
 
     private Map<String, String> getReplacements(
@@ -169,13 +164,13 @@ private String joinJsDelivrPath(String library, String cdnVersion, String cdnFil
         return CDN_JSDELIVR_NET_NPM + library + "@" + cdnVersion + "/" + cdnFileName;
     }
 
-    private String constructGraphQlEndpoint(HttpServletRequest request, @RequestParam Map<String, String> params) {
+    private String constructGraphQlEndpoint(String contextPath, @RequestParam Map<String, String> params) {
         String endpoint = graphiQLProperties.getEndpoint().getGraphql();
         for (Map.Entry<String, String> param : params.entrySet()) {
             endpoint = endpoint.replaceAll("\\{" + param.getKey() + "}", param.getValue());
         }
-        if (StringUtils.isNotBlank(request.getContextPath()) && !endpoint.startsWith(request.getContextPath())) {
-            return request.getContextPath() + endpoint;
+        if (StringUtils.isNotBlank(contextPath) && !endpoint.startsWith(contextPath)) {
+            return contextPath + endpoint;
         }
         return endpoint;
     }

graphiql-spring-boot-autoconfigure/src/main/java/com/oembedler/moon/graphiql/boot/ReactiveGraphiQLController.java

@@ -0,0 +1,48 @@
+package com.oembedler.moon.graphiql.boot;
+
+import lombok.extern.slf4j.Slf4j;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.text.StrSubstitutor;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.core.io.buffer.DataBufferFactory;
+import org.springframework.core.io.buffer.DefaultDataBufferFactory;
+import org.springframework.http.MediaType;
+import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.http.server.reactive.ServerHttpResponse;
+import org.springframework.stereotype.Controller;
+import org.springframework.util.StreamUtils;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import reactor.core.publisher.Mono;
+
+import javax.annotation.PostConstruct;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.Charset;
+import java.util.HashMap;
+import java.util.Map;
+
+@Slf4j
+@Controller
+public class ReactiveGraphiQLController extends GraphiQLController {
+
+  private DataBufferFactory dataBufferFactory = new DefaultDataBufferFactory();
+
+  @PostConstruct
+  public void onceConstructed() throws IOException {
+    super.onceConstructed();
+  }
+
+  @RequestMapping(value = "${graphiql.mapping:/api}")
+  public Mono<Void> graphiql(ServerHttpRequest request, ServerHttpResponse response,
+                             @PathVariable Map<String, String> params) {
+    response.getHeaders().setContentType(MediaType.TEXT_HTML);
+    Object csrf = request.getQueryParams().getFirst("_csrf");
+    return response.writeWith(Mono.just(request.getPath().contextPath().value())
+        .map(contextPath -> super.graphiql(contextPath, params, csrf))
+        .map(dataBufferFactory::wrap));
+  }
+
+}

graphiql-spring-boot-autoconfigure/src/main/java/com/oembedler/moon/graphiql/boot/ServletGraphiQLController.java

@@ -0,0 +1,50 @@
+package com.oembedler.moon.graphiql.boot;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.commons.lang3.StringUtils;
+import org.apache.commons.lang3.text.StrSubstitutor;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.core.env.Environment;
+import org.springframework.core.io.ClassPathResource;
+import org.springframework.http.MediaType;
+import org.springframework.security.web.csrf.CsrfToken;
+import org.springframework.stereotype.Controller;
+import org.springframework.util.StreamUtils;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestParam;
+
+import javax.annotation.PostConstruct;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.Charset;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+
+/**
+ * @author Andrew Potter
+ */
+@Slf4j
+@Controller
+public class ServletGraphiQLController extends GraphiQLController{
+
+    @PostConstruct
+    public void onceConstructed() throws IOException {
+        super.onceConstructed();
+    }
+
+    @GetMapping(value = "${graphiql.mapping:/graphiql}")
+    public void graphiql(HttpServletRequest request, HttpServletResponse response,
+                         @PathVariable Map<String, String> params) throws IOException {
+        response.setContentType("text/html; charset=UTF-8");
+        Object csrf = request.getAttribute("_csrf");
+        byte[] graphiqlBytes = super.graphiql(request.getContextPath(), params, csrf);
+        response.getOutputStream().write(graphiqlBytes);
+    }
+
+}